This invention relates to telephone apparatus, and in particular to a device adapted for interposing in a telephone service line for testing of the service line and any telephone network attached to the service line.
In the past, the entire telephone network including the handset was owned and serviced by the provider of telephone services, normally a local telephone company. With modern divestitures, however, typically the telephone company owns only the service line leading to a building, with the building owner either owning or leasing the telephone line network within the building, and all telephone handsets connected to the telephone network. Since the telephone company no longer provides free service, it has become increasingly important for the building owner to be able to test his telephone network to assure its reliable operation and, when problems occur, quickly identify those problems, whether those problems have occurred in the service being provided to the building, the network within the building, or the handsets connected to the network.